Richard F. Heck Lectureship, Tamejiro Hiyama, Ph.D

Modern organic synthesis heavily depends on the fruitful potential of organometallic chemistry. This lecture will start with invention of Nozaki-Hiyama-Kishi reaction, which uses Cr(II) chlorides (in the presence of Ni halide for alkenyl iodide) to reduce C–halogen bonds. The invention and development of silicon-based cross coupling reaction (Hiyama Coupling), disclosed for the first time using trimethylvinylsilane with aryl iodides in the presence of Pd(II) catalyst and TASF, (Et2N)3S+F2SiMe3-, in HMPA, will next be discussed. What is the next target after the cross-coupling chemistry? An answer to this question, we consider, should be direct use of otherwise stable C–C or C–H bonds for making new C–C bonds. An approach is C–CN bond activation, leading to carbocyanation reaction, for which a combination of nickel(0)/phosphine and Lewis acid is extremely effective and a variety of nitriles are applicable to the reaction with internal alkynes. An alternative involves C–H bond activation followed by C–C bond formation, a contemporary topic in organic synthesis. In summary, various combinations of catalyst systems are found to have potency for invention of unknown synthetic transformations. We believe novel reaction only produces novel structure, which definitely exhibits novel function that should be useful in the future synthetic technology. In this way, organic synthesis will continue to contribute to the progress in the medicinal and material science.